Characterizing swallowing abnormalities in progressive supranuclear palsy

Abstract

The dysphagia that occurs as an early sign of progressive supranuclear palsy (PSP), and which may predispose patients to aspiration pneumonia, has never been fully characterized. We evaluated 27 patients (mean ± SEM age, 64.9 ± 1 years; symptom duration, 52 ± 5 months) who met the clinical National Institute of Neurological Disorders and Stroke and Society for PSP (NINDS-SPSP) criteria for possible or probable PSP, with a swallowing questionnaire, an oral motor and speech examination, and either a modified barium swallow or ultrasound studies. Twenty-eight age- and sex-matched healthy controls (age, 65.6 ± 1.5 years) were also evaluated with the questionnaire, oral examination, and the ultrasound study. We used ANOVA statistics to evaluate differences between groups; nonparametric correlations to assess associations between swallowing and motor and cognitive abnormalities; and logistic regression analysis to determine if the items of the questionnaire or oral examination predicted ultrasound or modified barium swallow abnormalities. While PSP patients had at least one complaint on the swallowing questionnaire (mean, 6.6), healthy controls had fewer and less relevant complaints (0.3). Patients with moderate-to-severe cognitive disabilities had significantly more complaints of dysphagia than those with mild or no impairment. PSP patients' oral motor skills and speech were mildly impaired but significantly different from those of controls. In the ultrasound studies, PSP patients had significantly fewer continuous swallows and required a longer duration to complete their swallows than did healthy controls. They also had mild-to-moderate abnormalities in the modified barium swallow study. The swallowing questionnaire, oral motor examination, and speech production examination accurately predicted the abnormalities detected with the swallowing studies. While 75% of patients had abnormal speech, all but one had abnormal swallowing studies. Thus, although dysphagia is associated with dysarthria, the two conditions are not always paired in the same patient. Our results suggest that the swallowing questionnaire and oral motor examination are an easy and cost-effective method to predict the swallowing disturbances in PSP.